Modify Granite Countertop

jerryk1234

Hello,

The short version:

* I bought a house. It was a foreclosure. Forces of Evil removed all the appliances,
including the cooktop.

We want a different cooktop. It's a Capital. A serious piece of equipment, but it's bigger than the old one, although they're both nominally 36 inches. I'll have to cut an inch and a quarter off the front of the hole. That's not going to leave much granite along the front. And even less plywood under it.

There's a gap of a quarter inch between the front lip of the granite and its supporting plywood. Before cutting this granite, I plan to sneak a strip of quarter inch plywood in there to give the granite more support.

Comments?

- JerryK

Just Bill

Not much there for support. My guess would looking at several small pieces of granite on the floor. Consult an expert, might be worth it.

jerryk1234

*** Could be. There's a piece of beveled cosmetic wood right under that lip. A false drawer front. I plan to have the 1/4 inch plywood rest on the top of the false drawer front. And screw a substantial piece of plywood to the back of the false front, entirely filling the drawer hole. That will convert the minimal strip of wood under the granite, into solid wood, transferring the load further down into the cabinet.

I am going to do this even if I don't do any hole enlargment modifications ( and reinstall the original make & model of cooktop ), because the I feel that the original installation was badly done.

Another trick I just thought of would be to make a temporary support for the lip out of plywood or 2x4s or whatever....

- JerryK

rossfingal

"jerryk1234"
Take "Just Bill"s advice - go to a place that installs granite counter tops;
and, have them look at it.
What it sounds like you have, is inadequate support along the front edge.
A gap of 1/4" between the granite and what's supporting it?! -
not good!!!
We've dealt with granite counter tops - I'm not sure altering one is a DIY
project.
My opinion.
(However - almost, anything can be done)

rossfingal

jerryk1234

*** The gap is not between the granite and the wood. The granite
touches the wood - more or less. Since there is such little wood,
it bowed down when they were installing it, and there are shims
between the bowed down wood and the granite. And a blob of epoxy at each shim.

The quarter inch I speak of, is between the wood support and the doubled LIP of the granite. In other words, the granite sticks out into thin air a quarter of an inch before the doubling starts. I'll try to take some pictures. They'll come in handy also if I go to granite shops with
my problem....

I have seen this space between cabinetry and doubled lip before on other installations. In fact, we had a countertop done with 5" of granite
sticking out into mid-air. The granite guys said that was perfectly OK. I insisted on korbels to at least make it *look* supported.

(However - almost, anything can be done)
[/quote]
*** Youtube videos lead me to believe that cutting granite is not a big deal. You use an angle grinder and a diamond blade. Makes lots of dust
if you do it dry. I have put in plenty of time behind angle grinders - but cutting, grinding and sanding *metal*.

- JerryK

rossfingal

JerryK
Don't follow everything you see on You-Tube! (wink-wink!)
I've seen granite "hung over" the edge, 12 to 18 inches - no problem.
Depends on the installation.
I'm not saying it can't be done - whether or not it's advisable -
that's another story.
Yes - post some pictures.

rossfingal

jerryk1234

*** The plan was to go to the granite yard and buy some scraps to practice on. Mostly I worry about the angle grinder getting away from me.

Marbledust

Sounds like the remaining granite edge(after you remove 1 1/4")will be about 1 1/2" wide?
can you add pencil rod steel in the front gap??apply rod with epoxy,let it cure,than use masking tape to mark the cut area.use your angle grinder,apply water to the blade with a wet sponge.make shallow cuts.

jerryk1234

*** I'll do measurements and pictures today.

[quote=Marbledust;727228]
can you add pencil rod steel in the front gap??
*** Possibly. I could use a drill bit set to gauge the width
of the gap. I didn't think of steel.

What I have is some 1/4" ( or closest metric equivalent ) aircraft grade
TWELVE-PLY plywood ( imported from Finland ).

http://www.aircraftspruce.com/catalo...nnishbirch.php.

This stuff is extremely dense and strong. I honestly believe it is stiffer than steel. It doesn't cut like wood at all - more like some kind of plastic.

md2lgyk

Why can't you the 1-1/4 inch from the back of the hole? Or half of that from both?

jerryk1234

OK, here are some pictures.
First, the front of the cabinet, showing the minimal support for the granite lip:


Then from the top, showing where the L/H cut line will be.



Then a view under the front lip, showing how much ( or little! ) wood there is:


Then a view of the top front. The forward edge of the level is right on the cut line.


Here's the strip of aircraft grade plywood to fit in the slot in front:


Strip of plywood sliding into the lip:


Strip of plywood farther into the lip:


Strip of plywood loosely captured by false front. It is resting on top of the false front, which becomes a structural member. The false front will transfer load from the middle of the granite lip to the bottom edges of that particular cabinet bay. By "edges", I mean the L/H and R/H edges. That's where the cabinet is stiff. There will be a piece of 1/2" or 3/4" plywood completely filling the drawer hole that the false front covers.



False front rammed home up against the plywood strip. Note that the gap between the false front and the actual drawer under it is proper. The plywood strip disappears almost completely.


I will also epoxy the plywood strip into the slot. Yeah, it's belt and suspenders.

Dimensions:

The existing front lip is 3 7/8" wide. I will have to cut it down to 2 5/8".
The bullnose is 1 9/16" thick, so the granite itself is half of that, or approx 20mm.

The existing wood under that lip is 2.05" wide. After the cut, there will be 0.925" left. With my quarter inch of plywood, that gets us 1.175 inches of support. Call it 1 1/8".

- JerryK

jerryk1234

*** You know, I actually could. I thought I couldn't because the
manual for the stove specifies 2.5 inches of clearance from the backsplash.
But I talked to tech support for the stove yesterday, and he told me that the 2.5 inches is actually from *combustibles* at the back. From a non-combustible granite backsplash, less distance is needed. More like
1 1/4" IIRC. So I do have 0.875 inches that I could cut off at the back.
Supposing I cut 1/2 inch at the back, that leaves me only 3/4" to cut off at the front. MUCH better. Thanks!

- JerryK

jerryk1234

Update: We decided to go for the same Frigidaire Professional cooktop that was installed before. Which means no cutting the granite. Also saved us $500 on
the appliance. It's not quite as pretty as the Capital, and only 17000 BTU on that central burner ( as opposed to 20,000 on the Capital ). We went down to
the store and bought the appliances. So that's a done deal.

I will still however install the reinforcement to the forward lip.

- JerryK

mossypath

I am missing something, I would think you could cut a piece of 3/4 ply to fill the space behind the false front. More than enough support for what you are trying to do.

jerryk1234

*** Belt & Suspenders. I did cut the 3/4 ply and fill the space behind the false front. I even duplicated the sag in the original cabinet-top ( which was shimmed to the plywood that supports the granite. I epoxied the 3/4 ply into the hole.

I *also* did the 1/4" aircraft plywood strip in the space behind the lip.
AND
I rammed the cosmetic front up to the 1/4" strip and screwed it into the 3/4 ply. So the quarter inch stiffening strip rests on the cosmetic front.

And last but not least, I went back to the original make & model of cooktop, so I didn't have to cut the granite.

A hint that the original support was not adequate was supplied in the form of two cracks: one at the L/H edge, and one in the middle ( of the forward lip ).

- JerryK